A235924 - cp's OEIS frontend

A235924 a(n) = |{0 < k < n: p = phi(k) + phi(n-k)/3 + 1, q = prime(p) - p + 1 and r = prime(q) - q + 1 are all prime}|, where phi(.) is Euler's totient function.

n	a(n)
1	0
2	0
3	0
4	0
5	0
6	0
7	0
8	0
9	0
10	1
11	1
12	1
13	2
14	0
15	1
16	0
17	1
18	1
19	0
20	1
21	1
22	1
23	0
24	1
25	0
26	1
27	0
28	0
29	0
30	1
31	0
32	2
33	0
34	3
35	0
36	1
37	0
38	2
39	3
40	4
41	3
42	3
43	1
44	2
45	3
46	1
47	6
48	2
49	9
50	2
51	5
52	3
53	4
54	3
55	8
56	1
57	4
58	3
59	9
60	2
61	3
62	5
63	6
64	6
65	7
66	3
67	8
68	7
69	6
70	4
71	4
72	5
73	7
74	3
75	6
76	5
77	1
78	4
79	6
80	6
81	2
82	3
83	4
84	5
85	4
86	11
87	4
88	5
89	4
90	7
91	2
92	5
93	5
94	5
95	2
96	6
97	2
98	5
99	5
100	7

[0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 2, 0, 1, 0, 1, 1, 0, 1, 1, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 2, 0, 3, 0, 1, 0, 2, 3, 4, 3, 3, 1, 2, 3, 1, 6, 2, 9, 2, 5, 3, 4, 3, 8, 1, 4, 3, 9, 2, 3, 5, 6, 6, 7, 3, 8, 7, 6, 4, 4, 5, 7, 3, 6, 5, 1, 4, 6, 6, 2, 3, 4, 5, 4, 11, 4, 5, 4, 7, 2, 5, 5, 5, 2, 6, 2, 5, 5, 7]

cp's OEIS Frontend

A235924 a(n) = |{0 < k < n: p = phi(k) + phi(n-k)/3 + 1, q = prime(p) - p + 1 and r = prime(q) - q + 1 are all prime}|, where phi(.) is Euler's totient function.

Table of values

List of values

n	a(n)
1	0
2	0
3	0
4	0
5	0
6	0
7	0
8	0
9	0
10	1
11	1
12	1
13	2
14	0
15	1
16	0
17	1
18	1
19	0
20	1
21	1
22	1
23	0
24	1
25	0
26	1
27	0
28	0
29	0
30	1
31	0
32	2
33	0
34	3
35	0
36	1
37	0
38	2
39	3
40	4
41	3
42	3
43	1
44	2
45	3
46	1
47	6
48	2
49	9
50	2
51	5
52	3
53	4
54	3
55	8
56	1
57	4
58	3
59	9
60	2
61	3
62	5
63	6
64	6
65	7
66	3
67	8
68	7
69	6
70	4
71	4
72	5
73	7
74	3
75	6
76	5
77	1
78	4
79	6
80	6
81	2
82	3
83	4
84	5
85	4
86	11
87	4
88	5
89	4
90	7
91	2
92	5
93	5
94	5
95	2
96	6
97	2
98	5
99	5
100	7

n	a(n)
1	0
2	0
3	0
4	0
5	0
6	0
7	0
8	0
9	0
10	1
11	1
12	1
13	2
14	0
15	1
16	0
17	1
18	1
19	0
20	1
21	1
22	1
23	0
24	1
25	0
26	1
27	0
28	0
29	0
30	1
31	0
32	2
33	0
34	3
35	0
36	1
37	0
38	2
39	3
40	4
41	3
42	3
43	1
44	2
45	3
46	1
47	6
48	2
49	9
50	2
51	5
52	3
53	4
54	3
55	8
56	1
57	4
58	3
59	9
60	2
61	3
62	5
63	6
64	6
65	7
66	3
67	8
68	7
69	6
70	4
71	4
72	5
73	7
74	3
75	6
76	5
77	1
78	4
79	6
80	6
81	2
82	3
83	4
84	5
85	4
86	11
87	4
88	5
89	4
90	7
91	2
92	5
93	5
94	5
95	2
96	6
97	2
98	5
99	5
100	7

n	a(n)
1	0
2	0
3	0
4	0
5	0
6	0
7	0
8	0
9	0
10	1
11	1
12	1
13	2
14	0
15	1
16	0
17	1
18	1
19	0
20	1
21	1
22	1
23	0
24	1
25	0
26	1
27	0
28	0
29	0
30	1
31	0
32	2
33	0
34	3
35	0
36	1
37	0
38	2
39	3
40	4
41	3
42	3
43	1
44	2
45	3
46	1
47	6
48	2
49	9
50	2
51	5
52	3
53	4
54	3
55	8
56	1
57	4
58	3
59	9
60	2
61	3
62	5
63	6
64	6
65	7
66	3
67	8
68	7
69	6
70	4
71	4
72	5
73	7
74	3
75	6
76	5
77	1
78	4
79	6
80	6
81	2
82	3
83	4
84	5
85	4
86	11
87	4
88	5
89	4
90	7
91	2
92	5
93	5
94	5
95	2
96	6
97	2
98	5
99	5
100	7